Segmentation fault after linking Rust staticlib with C -

i'm trying link statically against library written in rust:

#![crate_type = "staticlib"]  #[no_mangle] pub extern "c" fn foo() {     println!("bork!"); } 

using following code in c:

void foo(); int main() {     foo();     return 0; } 

compile lib rustc:

rustc foo.rs 

compile binary , link library:

gcc -g bar.c libfoo.a -ldl -lpthread -lrt -lgcc_s -lpthread -lc -lm -o bar 

run inside debugger:

(gdb) run starting program: /home/kykc/rusttest/bar  [thread debugging using libthread_db enabled] using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".  program received signal sigsegv, segmentation fault. 0x00007ffff72117df in __cxa_thread_atexit_impl (func=<optimized out>, obj=<optimized out>, dso_symbol=0x0) @ cxa_thread_atexit_impl.c:67 67  cxa_thread_atexit_impl.c: no such file or directory. 

gcc:

gcc-4.8.real (ubuntu 4.8.2-19ubuntu1) 4.8.2 

rustc:

rustc 1.0.0-beta (9854143cb 2015-04-02) (built 2015-04-02) 

it works fine dylib. doing wrong?

the problem here thread-locals destructors can used in position-independent executables (due a bug) . fix: pass -pie flag gcc, or wait day or two.

this caused std::io::stdio::_print , std::io::stdio::local_stdout in standard library:

/// stdout used print! , println! macros thread_local! {     static local_stdout: refcell<option<box<write + send>>> = {         refcell::new(none)     } }  // ...  pub fn _print(args: fmt::arguments) {     let result = local_stdout.with(|s| {         if s.borrow_state() == borrowstate::unused {             if let some(w) = s.borrow_mut().as_mut() {                 return w.write_fmt(args);             }         }         stdout().write_fmt(args)     });     if let err(e) = result {         panic!("failed printing stdout: {}", e);     } } 

the box in local_stdout has destructor in case, executable crashes when thread-local variable touched. i've filed #24445, , alex crichton has diagnosed , fixed underlying cause already.

printing doesn't require initialising threads or anything; there's fallback stdout() in case local_stdout contains none (which default). passing -pie enough convince executable print bork! instead of crashing.